import java.util.Scanner;

/**
 * Created by 86135 on 2020/2/19.
 */
public class Test08 {
    public static void main(String[] args) {

        int[] arr = {21,19,12,39,46,76,23,92,37,54,25,74,20,13,53};
        int a = search(arr);
        System.out.println(a);

    }
    public static int search(int[] arr){
        int flag = -1;
        Scanner sc = new Scanner(System.in);
        int a = sc.nextInt();
        for (int i = 0; i < arr.length; i++) {

            if (a == arr[i]){
                flag = i;
            }
        }
        return flag;
    }
}
